With the development towards full color gamut, low color shift, and high resolution, there is a higher requirement for the reliability of Thin Film Transistor Liquid Crystal Display (TFT-LCD) products. When a same still image is displayed in a TFT-LCD for a long time, the liquid crystal molecules cannot rotate normally under the control of the signal voltage since the liquid crystal molecules are polarized after being driven for a long time. Consequently, when the image displayed therein is changed after a certain time period, the trace of the previous still image can yet be seen. That is, the afterimage of the previous still image is left.